This section provides background information related to the present disclosure which is not necessarily prior art.
Exhaust gas treatment devices such as catalytic converters, diesel oxidation catalysts, diesel particulate filters, and the like, may be employed in various systems to treat exhaust gases emitted from internal combustion engines. Many of the exhaust gas treatment systems include several subcomponents separated by a distance. Furthermore, many of the independent exhaust treatment devices include housings having multiple panels and supports to define different chambers and mount various elements within the exhaust treatment device.
Some of the known exhaust treatment systems include a reductant injector and a reductant decomposition device positioned upstream of a selective catalytic reduction device (SCR). While several known SCR systems have functioned properly in the past, concerns arise regarding controlling the decomposition of urea to ammonia. Many of the prior systems required an upstream decomposition tube wrapped with relatively cumbersome and expensive insulation to retain heat within the tube. Unfortunately, the SCR systems have become relatively large, costly and possible cumbersome.
Furthermore, some exhaust treatment device housings are formed using stamped metal sheets to define split or “clam shell” designs. As such, inner housings and outer housings may be formed from separate clam shell components. Additional stampings may be formed and welded to the clam shells to provide an exhaust inlet, and exhaust outlet and sometimes another inlet for injecting reagents into the exhaust stream. Some exhaust treatment device housings have become relatively complex, costly and difficult to assemble. Accordingly, it may be desirable to provide an improved exhaust treatment device having an integral decomposition tube exhibiting reduced size, cost and complexity.